I've wondered about that, too... there must be forensic photo analysis software made for that sort of thing that detects pixel irregularities, or something. Sometimes the edges/borders of elements are unnaturally jagged, or the lighting is clearly different in parts of the photo-- those can be tells.
I know that photos can contain metadata, and maybe date/time/location/whether it was made in photoshop/etc. information coded into the image could offer up some clues in certain cases (though that can be faked, too).
But yes, it's true, you can't really trust your eyes...
Hi kindstranger, thanks for Value Clarifications
If you find an image-detection program or videos, point me out and I am very grateful for your great efforts!!!
I wish good luck to all, with more sustained work for financial freedom.